Euclidean nearest neighbor distance (ENN) is perhaps the simplest measure of patch isolation. Here, nearest neighbor distance is defined using simple Euclidean geometry as the shortest straight-line distance between the focal patch and its nearest neighbor of the same class, based on the distancebetween the cell centers of the two closest cells from the respective patches.

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CONTIG(Contiguity Index)

Contiguity index assesses the spatial connectedness, or contiguity, of cells within a grid-cell patch to provide an index on p

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PARA (Perimeter-Area Ratio)

Perimeter-area ratio is a simple measure of shape complexity, but without standardization to a simple Euclidean shape (e.g., square). A problem with this metric as a shape index is that it varies with the size of the patch. For example, holding shape constant, an increase in patch size will cause a decrease in the perimeter-area ratio.